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<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
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<body>
    <script>
        // //定义函数
        // fn = () => {
        //     console.log('666');
        // }
        // // 调用函数
        // fn()
        function fu(a,b){
            this.a=a+5
            this.b=b+5
            return this.a+this.b
        }

       let sum= fu(1)
        console.log(sum);
        console.log(a,b);
    </script>
</body>

</html>